In surgical operations of the chest or abdomen, it is customary to employ a retraction apparatus to retain tissue away from the operative site. Such a retractor system is shown in U.S. Pat. Nos. 4,254,763, and in 4,424,724. The retractor shown in U.S. Pat. No. 4,424,724 is a multi-position ratchet mechanism which permits a retractor blade to be rotated into the wound and retracted at the same time to duplicate the natural toe-in method of retraction achieved if the retractor was held by hand. These ratchet mechanism are employed in a surgical retractor assembly which includes a support post which attaches directly to the surgical operating table. An extension arm may be attached to the support post for supporting an oval or round or other shape ring above the surgical incision. One or more retractor blades can be attached to the ring by means of the retractor ratchet mechanisms. Retractor blades of different sizes and shapes may be used to obtain the desired positioning and retraction of internal organs and tissue so that the operative site may be completely exposed for the surgeon. In the retractor system shown in the U.S. Pat. No. 4,424,724, the retractor can be rotated by tilting the blade into the wound so that organs can be retracted and lifted at the same time. It is particularly advantageous to be able to retract toward the ring to obtain exposure under an organ, such as lifting on the thoracic cage to reach a hiatal hernia. By rotating the blade down into the wound, and then lifting and retracting at the same time, one duplicates the natural "toe-in" method of retraction that would be achieved by the hand. This type of retraction enables the surgeon to see the underlying organs better than if the retractor can only move away from the operative site without lifting. The ability to lift the retractor blade also enables a single retractor blade to be used at different depth rather than to use different retractor blades for different depths in the body.
The retractor ratchet system shown in U.S. Pat. No. 4,424,724 employs two ratchet mechanism to allow the tilting movement and the movement of the retractor blade stem in an out of the operative area of the patent. In order to adjust the ratchet mechanism two pawls in two different positions on the ratchet mechanism must be activated. It is therefore difficult to adjust both the tilting of the retractor and the position of the retractor blade at the same time. In order to move the reactor blade in and out of the wound area, one ratchet must be disengaged by applying pressure on a ratchet release mechanism and then moving the blade to the desired position. In order to tilt the ratchet mechanism, a second activating mechanism must be depressed to disengage a second ratchet. Because of the relative positions of these two disengagement mechanisms, it is cumbersome to disengage both mechanisms with one hand. It would be advantageous to have a ratchet mechanism in which both the tilt and the movement of the retractor blade in and out of the wound site could be controlled with a single lever to simultaneously release both ratchets so that the retractor blade could be positioned easily.